diff --git a/ports/vtk/opencascade-7.8.0.patch b/ports/vtk/opencascade-7.8.0.patch
new file mode 100644
index 0000000000..3a78b0a38a
--- /dev/null
+++ b/ports/vtk/opencascade-7.8.0.patch
@@ -0,0 +1,83 @@
+diff --git a/IO/OCCT/CMakeLists.txt b/IO/OCCT/CMakeLists.txt
+index e81444eceb..4baddeb719 100644
+--- a/IO/OCCT/CMakeLists.txt
++++ b/IO/OCCT/CMakeLists.txt
+@@ -4,12 +4,25 @@ vtk_module_find_package(PRIVATE_IF_SHARED
+   VERSION_VAR "@OpenCASCADE_MAJOR_VERSION@.@OpenCASCADE_MINOR_VERSION@.@OpenCASCADE_MAINTENANCE_VERSION@"
+ )
+ 
+-set(opencascade_req_targets
+-  TKSTEP
+-  TKIGES
+-  TKMesh
+-  TKXDESTEP
+-  TKXDEIGES)
++if (OpenCASCADE_VERSION VERSION_GREATER_EQUAL "7.8.0")
++  set(opencascade_req_targets
++    TKDESTEP
++    TKDEIGES
++    TKernel
++    TKMath
++    TKMesh
++    TKBRep
++    TKXSBase
++    TKLCAF
++    TKXCAF)
++else()
++  set(opencascade_req_targets
++    TKSTEP
++    TKIGES
++    TKMesh
++    TKXDESTEP
++    TKXDEIGES)
++endif()
+ set(opencascade_missing_targets)
+ foreach (opencascade_req_target IN LISTS opencascade_req_targets)
+   if (NOT TARGET "${opencascade_req_target}")
+@@ -35,8 +48,7 @@ vtk_module_link(VTK::IOOCCT
+     ${opencascade_req_targets})
+ 
+ # OpenCASCADE started putting include directory usage requirements in 7.7.0.
+-set(OpenCASCADE_VERSION
+-  "${OpenCASCADE_MAJOR_VERSION}.${OpenCASCADE_MINOR_VERSION}.${OpenCASCADE_MAINTENANCE_VERSION}")
++
+ if (OpenCASCADE_VERSION VERSION_LESS "7.7.0")
+   vtk_module_include(VTK::IOOCCT PRIVATE "${OpenCASCADE_INCLUDE_DIR}")
+ endif ()
+diff --git a/IO/OCCT/vtkOCCTReader.cxx b/IO/OCCT/vtkOCCTReader.cxx
+index 52e76be72c..5aca5c93c8 100644
+--- a/IO/OCCT/vtkOCCTReader.cxx
++++ b/IO/OCCT/vtkOCCTReader.cxx
+@@ -345,11 +345,19 @@ public:
+   }
+ 
+   //----------------------------------------------------------------------------
++#if VTK_OCCT_VERSION(7, 8, 0) <= OCC_VERSION_HEX
++  size_t GetHash(const TDF_Label& label)
++  {
++    TopoDS_Shape aShape;
++    return this->ShapeTool->GetShape(label, aShape) ? std::hash<TopoDS_Shape>{}(aShape) : 0;
++  }
++#else
+   int GetHash(const TDF_Label& label)
+   {
+     TopoDS_Shape aShape;
+     return this->ShapeTool->GetShape(label, aShape) ? aShape.HashCode(INT_MAX) : 0;
+   }
++#endif
+ 
+   //----------------------------------------------------------------------------
+   static void GetMatrix(const TopLoc_Location& loc, vtkMatrix4x4* mat)
+@@ -381,8 +389,11 @@ public:
+       GetMatrix(hLoc->Get(), location);
+     }
+   }
+-
++#if VTK_OCCT_VERSION(7, 8, 0) <= OCC_VERSION_HEX
++  std::unordered_map<size_t, vtkSmartPointer<vtkPolyData>> ShapeMap;
++#else
+   std::unordered_map<int, vtkSmartPointer<vtkPolyData>> ShapeMap;
++#endif
+   Handle(XCAFDoc_ShapeTool) ShapeTool;
+   Handle(XCAFDoc_ColorTool) ColorTool;
+ 
diff --git a/ports/vtk/portfile.cmake b/ports/vtk/portfile.cmake
index 1c38959c52..1d79e39e8d 100644
--- a/ports/vtk/portfile.cmake
+++ b/ports/vtk/portfile.cmake
@@ -39,6 +39,7 @@ vcpkg_from_github(
         10945.diff
         10972.diff
         hdf5helper.patch
+        opencascade-7.8.0.patch
 )
 
 # =============================================================================
@@ -121,6 +122,7 @@ vcpkg_check_features(OUT_FEATURE_OPTIONS VTK_FEATURE_OPTIONS
         "openvr"      VTK_MODULE_ENABLE_VTK_RenderingOpenVR
         "gdal"        VTK_MODULE_ENABLE_VTK_IOGDAL
         "geojson"     VTK_MODULE_ENABLE_VTK_IOGeoJSON
+        "ioocct"      VTK_MODULE_ENABLE_VTK_IOOCCT
 )
 
 # Replace common value to vtk value
diff --git a/ports/vtk/vcpkg.json b/ports/vtk/vcpkg.json
index aff92ee0e7..e64aded01b 100644
--- a/ports/vtk/vcpkg.json
+++ b/ports/vtk/vcpkg.json
@@ -1,7 +1,7 @@
 {
   "name": "vtk",
   "version-semver": "9.3.0-pv5.12.0",
-  "port-version": 3,
+  "port-version": 4,
   "description": "Software system for 3D computer graphics, image processing, and visualization",
   "homepage": "https://github.com/Kitware/VTK",
   "license": "BSD-3-Clause",
@@ -117,6 +117,15 @@
     "geojson": {
       "description": "Convert Geo JSON format to vtkPolyData"
     },
+    "ioocct": {
+      "description": "Build with IOOCCT module",
+      "dependencies": [
+        {
+          "name": "opencascade",
+          "default-features": false
+        }
+      ]
+    },
     "mpi": {
       "description": "MPI functionality for VTK",
       "dependencies": [
diff --git a/versions/baseline.json b/versions/baseline.json
index 0b9ad21e45..bbe78b18ba 100644
--- a/versions/baseline.json
+++ b/versions/baseline.json
@@ -9214,7 +9214,7 @@
     },
     "vtk": {
       "baseline": "9.3.0-pv5.12.0",
-      "port-version": 3
+      "port-version": 4
     },
     "vtk-dicom": {
       "baseline": "0.8.14",
diff --git a/versions/v-/vtk.json b/versions/v-/vtk.json
index 1cf8ff1c5e..ad4e922797 100644
--- a/versions/v-/vtk.json
+++ b/versions/v-/vtk.json
@@ -1,5 +1,10 @@
 {
   "versions": [
+    {
+      "git-tree": "679af6f82484acf134c028480564699523c988ed",
+      "version-semver": "9.3.0-pv5.12.0",
+      "port-version": 4
+    },
     {
       "git-tree": "0bb2f77c2eeff358d3be93b1d5f0d006573137b7",
       "version-semver": "9.3.0-pv5.12.0",